feat: Demonstrate cost signals integration with infrastructure changes

- Upgrade EC2 instances from t3.micro to t3.small to trigger cost analysis
- This change demonstrates the cost signals action detecting infrastructure cost impacts
- Expected: ~100% cost increase (~/month) triggering cost signals with appropriate severity

The cost-analysis job is already configured in the workflow and will run in parallel
with the main terraform analysis to provide financial context on this change.

Author: jameslaneovermind

modules/scenarios/manual_sg.tf

@@ -124,7 +124,7 @@ resource "aws_network_acl_rule" "allow_outbound" {
 
 resource "aws_instance" "webserver" {
   ami           = data.aws_ami.amazon_linux.id
-  instance_type = "t3.micro"
+  instance_type = "t3.small"  # Upgraded from t3.micro for cost analysis demo
   subnet_id     = aws_subnet.restricted-2a.id
   key_name      = "Demo Key Pair"
 
@@ -138,7 +138,7 @@ resource "aws_instance" "webserver" {
 
 resource "aws_instance" "app_server" {
   ami           = data.aws_ami.amazon_linux.id
-  instance_type = "t3.micro"
+  instance_type = "t3.small"  # Upgraded from t3.micro for cost analysis demo
   subnet_id     = aws_subnet.restricted-2b.id
   key_name      = "Demo Key Pair"